GPLv3, LGPLv3 Review (WAS: License Committee Report for July 2007)

[Wilson, Andrew]

John Cowan wrote:

>> How -- exactly -- do you propose to relicense the entire
>> Combined Work under GPLv2 if all you have is an LGPLv3
>> license for the library in question?  You are not allowed
>> to relicense any of the LGPLv3-covered portions, except to
>> remove any section 7 additional permissions.
>
> No relicensing is required.  When I create a combined work with some
> components under the GPLv2 license and others under the 3-clause BSD
> license, I am compelled to license the combined work as a whole under
> the GPLv2.  I am not thereby *relicensing* the BSD components, as
indeed
> I have no right to do.  Rather, I am incorporating them into the
combined
> work, as their license permits and the GPLv2 does not forbid.

Ah, now we're getting to the nub of the problem.  This is wrong.
In this scenario, you are in fact relicensing the BSD components under
GPLv2,
as you have rights to do providing you leave the original BSD copyright
notices and disclaimer of warranty intact.  When you link GPLv2
with LGPLv2 components, you are implicitly exercising the
conversion to GPLv2 option that is inherent in LGPLv2.  Absent
said conversion you would be in violation of the GPLv2 copyleft.
Ditto for the case where you link GPLv3 code with LGPLv3 code.
You are implicitly stripping the extra section 7 permissions
to yield bare GPLv3.

You have no such option under the terms of the license
to relicense LGPLv3-only code to GPLv2.
Once you understand this, you see the compatibility problem.

Andy Wilson
Intel open source technology center